a(n) is the number of distinct pairs that can be made in exactly n iterations of either of the two maps (x, y) -> (x OR (2^y), 0) or (x, y) -> (x, y+1), starting from (0,0).

A353150

a(n) is the number of distinct pairs that can be made in exactly n iterations of either of the two maps (x, y) -> (x OR (2^y), 0) or (x, y) -> (x, y+1), starting from (0,0).